A question for public school teachers regarding tests

Does anyone create and/or use tests in their classrooms? I know in Korea, all testing was left for the NNS teacher to handle. Is it the same case here? I’m trying to pinpoint some research subjects for my thesis. Much thanks for any responses!

My co-teachers do it all.
And they give the tests out during their lessons and grade it themselves.

I have helped grade midterms and finals before because I offered to do so.